1. Field of the Invention
This invention refers to an arrangement of a bearing and box for ball joints that are applied to connections that demand angular and rotating movement of two pieces, and particularly for application to the rear shaft of light automotive vehicles.
2. Background of the Related Art
Related art ball joints require a sealing system to prevent impurities such as dust, sand and water penetrate in its interior and affect its operation due to the premature wearing out of its components, which must possess between themselves the best possible conformation, as after the mounting of the assembly, there is applied a certain load of displacement on the movable pieces, which load is generated by the friction of these moving pieces between themselves. Consequently, the presence of impurities between the pieces under friction tends to cause a premature wearing out of the components, affecting the performance of the ball joint. The ball joints at disposal for this purpose, generally are composed by a pin with a spherical section, which is coupled to a bearing, single or split in two pieces, such assembly being mounted in the interior of a box that thereafter is provided with orifices through were the non-spherical parts of the ball pin and the bearing are projected, that are sealed by sealing caps attached to a metallic ring that, by its turn, is retained between the box and the bearing, so as to prevent the entry of any impurity. At the ends of the box there are provided apertures, through which are projected the non-spherical parts of the pin, called ball pin body, where one of the pieces that need angular and rotating movement it is to be fixed, being the other piece fixed to the ball joint box by means of a bar. Thus, both the angular and rotating movement provided between the ball pin and the ball joint box must attend the needs of the pieces that are connected therein. However, to prevent the entry of impurities in the interior of the ball joint, at the ends of the box, through where the ball pin bodies penetrate, the sealing system must be perfect and efficient, even more because it is at these places that the ball pin performs its angular and rotating movements relative to the box.
The state of the art anticipates providing these places with sealing caps that are made of elastomer, with the two ends open, one of larger diameter to be coupled to a metallic ring (or collar) provided at the external part of the box and the other end of smaller diameter to be coupled to the body of the ball pin. In relation to the coupling of the outside part of the box the fixing of the sealing cap is normally made by providing between the box and the bearing, internally, a metallic ring that projects itself from the inner of the box, where are placed and fixed the ends of larger diameter of the sealing caps, after which the same are overlapped by an elastic ring, also called tightening ring, the purpose of which is to fix the sealing cap on the ring fixed to the box and to prevent the entry of any impurity, and, in relation to the coupling of the ball pin body, there is anticipated a ring, commonly called sealing ring, which aims to firmly fix the sealing cap on the ball pin body preventing the entry of impurities, but not impairing its rotating movement.
This fixing system of the sealing cap to the metallic ring attached to the box, however, has proven itself to be ineffective in consequence of some undesirable effects, related not only to its assembling process on the system, but also mainly due to the very manufacturing difficulties of the metallic ring that demand progressive tools for stamping of the ring, substantially increasing the cost of the piece and, consequently, the final cost of the ball joint.
The present invention aims to eliminate the undesirable effects of the prior art by providing a system with an arrangement that suppresses the metallic ring and formats an end of the bearing, so that, during its manufacturing process by injection the end of the bearing is formatted with the same material utilized for its injection, projecting said end to the outside of the box and providing it with a format similar to that of the metallic ring utilized in the usual arrangements and allowing, in this way, to be fixed to this projection the extremity of larger diameter of one of the sealing caps. With the same objective, that is, to eliminate the metallic ring, one of the extremities of the ball joint box is formatted during its manufacturing process by stamping process, providing a format similar to that of the metallic ring in order that one may fix, on this projection, the extremity of larger diameter of the other sealing cap. Thus, one of the sealing caps is fixed directly to the projection of the bearing and in the opposite side of the ball joint, while the other sealing cap is fixed directly to the projection of the ball joint box.